British bookmaker William Hill is to close more than 100 betting shops this year, blaming the decision on a tax increase on high-stakes gambling machines that have become one of their main sources of revenue. The UK government announced an increase in tax to 25 per cent from 20 per cent on the machines in its budget in March, a move that will cost bookmakers around £75 million a year. William Hill, Britain’s largest bookmaker, said the tax rise meant there was no prospect of turning around a group of 109 loss-making betting shops from a total estate of over…